Copper-catalyzed oxidative cross-dehydrogenative coupling of 2<i>H</i>-chromenes and terminal alkynes
作者:Fei Yang、Yangshan Li、Paul E. Floreancig、Xiaoyan Li、Lei Liu
DOI:10.1039/c8ob00949j
日期:——
An efficient copper-catalyzedcross-dehydrogenativecoupling of 2H-chromenes and terminal alkynes mediated by DDQ has been established. A protic additive, EtOH, proved to be crucial for harmonizing the oxidation with a subsequent alkynylation step by retaining the oxidation state of an oxocarbenium ion in the form of acetal. The CDC reaction exhibits a good substrate scope, with a range of terminal
Catalytic Asymmetric Addition of Aldehydes to Oxocarbenium Ions: A Dual Catalytic System for the Synthesis of Chromenes
作者:Magnus Rueping、Chandra M. R. Volla、Iuliana Atodiresei
DOI:10.1021/ol302084q
日期:2012.9.7
A synergistic catalytic system for the first asymmetric addition of aldehydes to in situ generated prochiral oxocarbenium ions has been developed. The dual catalytic protocol allows the simultaneous activation of both electrophile and nucleophile and provides access to a variety of valuable chiral 2H-chromenes with excellent enantioselectivities.
Kinetic Resolution and Dynamic Kinetic Resolution of Chromene by Rhodium‐Catalyzed Asymmetric Hydroarylation
作者:Qingjing Yang、Yanbo Wang、Shihui Luo、Jun (Joelle) Wang
DOI:10.1002/anie.201900721
日期:2019.4.8
A highly efficient kineticresolution and dynamickineticresolution of chromene is reported for the first time and they procced by a rhodium‐catalyzed asymmetric hydroarylation pathway. This new approach offers versatile access to various chiral 2,3‐diaryl‐chromanes containing vicinal stereogenic centers, as well as the recovered chiral flavenes, in high yields with excellent ee values (s factor up
Catalyst‐Free Synthesis of α‐Functionalized 2
<i>H</i>
‐Chromenes in Water: A Tandem Self‐Promoted
<i>pseudo</i>
‐Substitution and Decarboxylation Process
作者:Chunhui Jiang、Yayun Chen、Hongkui Zhang、Jian‐Ping Tan、Tianli Wang
DOI:10.1002/asia.201900641
日期:2019.9.2
protocol was also demonstrated by the scale-up synthesis and versatile conversions of the title product into other useful compounds. In addition, control experiments indicated that water was essential for the reactivity. Mechanistic studies further revealed that the reaction proceeded through a self-promoted tandem pseudo-substitution and decarboxylation process.